Automatic telephone-exchange system



March 30 1926.' 1,578,417

G. FRUBING AUTOMATIC TELEPHONE EXCHANGE SYSTEM Filed sept. 1, 1921Patented Mar. 3o, 1926;

UNITED STATES PATENT l oF'FlcE.l

HALSKE AKTIENGESELLSCHAFT, 0F WERNERWERK, SIEMENSSTADT, NEAR BER- LIN,GERMANY.

AUTOMATIC TELEPHONE-EXCHANGE SYSTEM.

Application led September 1, 1921. eria1 No. 497,679.

. l (GRANTED 'UNDER THE`IROVISIONS 0F THE ACT 0F MARGH 3, 1921, 41 STAT.L., 1313,)

i7 '0 all 10h30/m it may concern Be it known that I, GEORG FRBING, acitizen of the German Empire, Fesiding at Berlin-Vilmersdorf, Germany,have invented certain new and useful Improvements in AutomaticTelephone-Exchange ,Systems (for which` I have filed applications in Germany, May 2, 1916, Pat. No. 299,512, and Austria, May 2, 1917, Pat. No.80,904), of which the following is -a full, clear, concise, and eXactdescription. K

This invention relates to automatic telephone exchange systems andparticularly^to automatic telephone systems in which long distance ortoll connections are established.

by means :of the same connector switches used in establishingconnections between two 'local subscribers. y

Inv order to make possible the use of. the same connectors for the localand toll traffic, it has been proposed to provide toll operatorcontrolled switching means at theconnector, in addition to the switchingmeans controllable for the setting of the 'connector in a localconnection.

T he -drawback of such arrangement is that if the desired line, Which istemporarily seized by the connectorunder the control of a tolloperator,is idle, then, upon the seizure ot' this'line in response tothis preparatory setting up of the toll connection, the desired linewill be guarded against seizure. The temporary toll connection makesthedesired line busy t0 local subscribers although this line is not inactuall use.

It has been proposed to test and guard the local lines under the controllof switching apparatus associated with the connector and actuated atwill under control of the toll operator, rather than in response to thesetting of the connector switch onto ,the terminals of the desired line.This arrangement, however, contemplated the use of switching means inaddition to the switching means associated with the connector forcontrolling its setting, and therefore increased the cost ot operatipn.

It is the object of the present invention to provide a connectorarrangement whereby a toll connection may be prepared for completionWithut seizing .the called line, that is vmaking it test busy,andin-which the switching devices associated with the combinationconnector (for local and toll trailic) are reduced to aminimum. i

According to the main feature of the in.-

tol

vention, in response to tliepreparatory setting of a connector switch ina long distance connection, the' guarding of the desired local line andalso the further operations for completing the connection (testing ofthe desired line engaged in a. local or toll connection, establishmentof the talking circuit, supply of talking current, etc.), are operableunder the control of the toll operator, independently of operationsperformed during the setting of the connector. The cir- .cuits are soarranged thatthe toll operator when preparing the establishment of aconnection, isiirst connected to the desired local subscriber in orderto inform lhim of the longpdistance call if he is'engaged in a localponnection.

The complete establishment of the toll connection may be accomplishedunder the control of the toll operator in the same matr.

ner as the change-overirom the vertical to thev rotary motion `of theswitch isl accomplished, or in the same manner as the connector ischanged from local to long distance use.

According to another feature of the invention, the' completeestablishment of a prepared toll-connection is accomplishedv in responseto the same operationsvas are'performed upon the completed setting of aconnector on a line in a local connection, whereby, in addition to thetesting and guarding, I

of a local line desired in a toll connection, the desired line may besignaled under the control of the toll. operatorbythe ringingarrangement associated withsuch connector, and at the same time anexisting local connection may be severed.

'l In the drawings, Fig. 1 shows the circuits of the connector switch,arranged to be op-.-

of the various relays are not shown in their operative relations to suchrelays. The. armatures of each relay are marked by a small lettercorresponding to the capital designating the electromagnet of the relay.In order to distinguish between the various arclosing a circuit frombattery, xv,

matures of the` same relay, suflixes are used 1n addition to theletters. The relay ar'- matures are shown 1n their normal positions.

Sett/mg of the connector in a local connection. v

Upon the seizure of the trunk a, Z), c leading to the wipers of theconnector, relays A and B become energized in the well-known manner.Relay X does not become `energized because it is differentially wound.

vPrior to the sending out of impulses for causing the connector to move1n avertlcl direction, the calling subscriber depresses keys K1 and K2,

In orwhereupon relay-X becomes, closes its contacts switch wiper S1",and ma et SSM to'. ecomes ener-- ground. The magnet .SSM gized, anduponthe deener ization of relay X, the magnet becomes eenergized, and

vcauses the noyeliient of the side switchwip ers out of osition 1 intoposition 2. Prior to the sendlng out of the rotary impulses, the

relay Xfis againv energized as before.` By operating key 1K1 thesubscriber causes the Voperation of relay A, but now due to the factthat side switch wiper SVII is in its second position, therotary magnetRM is operated instead of the vertical magnet, and under-I l control ofthis magnet the wipers of the con` nector are rotated step by step.After the last rotar impulse has been sent out, relay X again circuitfrom grounded battery, through RON, w3, SVI, SSM to ground. c

The desired line is testedv 'n position 2 ,of the side switch. The relayB, upon its en-` ergization, closes a circuit vfrom ground through ON.1for relay U, which becomes energized and closes a lockingcircuitI forit-\ self through contact us. Oli-normal contacts ON1 open upon thefirst vertical step of the switch wipers. Relay U- by 'closing its confvtact U", prepares ,an energizing circuit for the I windlngof relay R,which circuit is completed Nupon the deenergization of relay X. Relay Rbecomes energized, and closes its 'contacts r3 and 719 for preparing theringing circuit. The relay R closes at itscontact T19 a circuit forrelay T, and if the line upon which'the connector switch is [set isidle, the test relay T becomes energized and t and 1512, whereupon theenergized.` Relay X closes contact thus ,.ringing circuit is corr letedand the called the lower half of the left winding of B to Relay B,being'slowito release, does not fall oli. Another circuit is closedfrombattery,

through av, the upper halt of the left winding of B, lower winding of\X, conductor b and key K2 to ground. The current which now flowsthrough the lower winding ofX isv in a direction to assist that through'the upper winding. The currentflowing through the lower halfof the-leftwinding of B is greater than that through the upper vhalf, and thus Bremains energized.4 In order to send out thevertical impulsres the calling subscriber operates key K1 fo operating relay A. Upon eachdeenergization,` relay A closes a 'circuit from grounded-battery,

.through w1, a2, VM, Smito ground. y Under the cont-rol ofthe Verticalmagnet, the .wip

ers off the connector are moved step by step in anv upward direction. fAftenthe sending out of the last vertical. impulse. the ground isdisconnected from the a' and b conductors,

' whereupon relay X becomes deenergized,

ilsubscriber is signaled. f The circuit for rela-y ground. Texterds'fromground through both wind;

ings'in ser-ies,contacts r1, wiper S', and test brifsh, tol contact 42,and thence to battery. Following testing, magnet 'SSMreceiVes an impulsethrough interrupter I1 and moves .thekside switch, wipers into positionl3.' In this .position of the side switch wipers, the winding II oftheringingA relay R is connected tothe interrupter I3, contact 1v of relayUbeingclosed. The interrupter Isis so arranged that the. ringing relayAis operated in 4intervals of ten seconds. U onthe removalof the receiverat the cal ed station, and during a silent peiod ofinterrupter I3,Qrelay'Y becomes energized. This relay by closing its' contacts A14:,short-circuits ,thewindingof relay U, which upon deenyergization' ope'nsat. its 'contact 'zt-13 the circuit Yof winding lII of thel ringingrelay;

l'.lheLtest relayfwhen energized, short-circuits 'its high resistancewindinggI 'in its contact t and thus guards the called line from seizureby other connectors; The local connection lis now completelyestablished.

If the desired line is busy, th'en.l in position 3 of the sideeswitch,,the test relay has eco'mes deenergized, and closes a notbecome-energized, and the calling party is informed in -thewell-knoWn-manner of -connection the desired subscriber restores hisreceiver to the switchliook, the relay Y b'ecomes deenergized, andconnects interruptcr I2 in circuit with the magnet SSM. Upon theenergization and subsequent deenergization of the magnet SSM, the sideswitch Wip- -ers are movedinto position 4. lVhile the side sivitchWipers are moving from position '3 to 4 and in position 4, the relay Tremains energized. The holding circuit of relay T may be traced l fromgrounded battery through resistance 4, SIX, TH, to ground. A circuit 'istherefore closed through `the test conductor c, S?, (posit-ion 4), t1",u2 and conductor a forcaiising the operation of the calling subscribersregister (not shown).l

vThe circuit closed to actua-te. the register, Aalso causes the releaseof'the selector by means of which the calling line has been eX- tendedto the connector, whereupony relays A and B become deenergized. Theabove described circuit is "then established for SSR and CR forreleasing the side switch and the ,connecten If the callingSiibscriberhangs up his re' ceiver after-a successful connection hasbeen established, then the above described 'regisi. i` circuit iscompleted from conductor c, through armature 622 of the relay B,Whereupon in response to the restoration ofthe re-v ceiver at the calledsubstation and the subsequent deenergization `of relay Y, the side--switch andthe connector are released in the above described manner.

Setting of the connector in atoll connection.

The connector is moved in a-vertical and rotary direction for seizingthe desired local line in the same manner as above` described and 'isunder the control of a toll operator whose sender comprises keys' (Fig-2) simi- A lar to those 'of alocal subscriber. After the last rotarimpulse has been sent out, the relay B` ecoines temporarily deenergized,due to the connection of an' opposing battery connection tothe bconductor at the sending statiomas by means of a key K3.

Relays A and X remain energized. The-fol:

lowing" circuit is now established: grounded The called line is nowft'ested.'

battery, b2", a2", Sn (position 2), relay V,

. to ground. Relay vV'becomesv energized and closes a locking circuitforitself through its armature V29' and the-armatiire a of relay A. `Inresponse to the temporary deenergization of relay B, relay U alsobecomes.

(leenergized. Due'to the fact, however, that relay X is energized andmaintains its ai'- mature m21 attracted, the release magnets of the sideswitch and the connectorare not operated. i

/ The tolll operator noiv'causes thel relay X to restore itsarmaturcsaaml relayB to pull.

up its armature, relay A being maintained operated. The magnet SSMreceives an iinpulse through interrupter 11- and the armature 3'of relayX, and causes the lmovement of the side switch Wipers out of position 2and .into position 3 iii the above Vdescribed manner. In this positionofthe side switch Wipers, the line on the terminals of which 'theconnector has been set isneither tested nor guarded, because relay Umaintains the circuits of relay R openl (in u andv 1013),;

and relay` RA in turn maintains the test cir' cuit open (in 911). Theconnector remains in the set position until' further' operated lunderthe control of the toll operator.' 'Thus Athe connector is set toVprepare a 4toil connection. l

As soon as the tollopera'tor decides to complete the 'toll connection,she will cause the temporary deenergization. of relay B and theenergization of relay X, as by operating keys K1 and K3 (Fig. 2). Thetoll loperatorcauses the energization of relay X byV Adepressing 'keyt'K1 as previously described, and. by Ioperating key K3, connectsv anopposing' battery to the conductor which causes the B relay to becomeitemporarily deenergized.v In response to the short deenergizat-ion ofthe relay B, the magnet SSM becomes energizedl and 'deener- 1 fgized'and moves theside switch wipers into position 4. The circuit maybetraced as follows: fromlgrounded battery by way of b2 and itsrestingcontact, a. and its wor ing' contact, side switch -Wiper SII inthird position, side switch Wiper SVI in third position thru sideswitchmagnet SSM to ground.

If the-called line vis enga ed ina toll iio connection, the test relay Tis s ort-circuited through a conne'ctorholding` the'ca`led 1in-e', theside switch wipers of this .connector being in position 8.- The magnetSSM is op ei'ated b interrupter .Iythe cont-act /vhof relay -.beingclosed. wipers then move into position 5, and in viewof the'factthatrela-y T is not ener- "gized, a. circuit..is closed from" groiinl' Theside switch` through fthe, secondary'iwinding of a toll .A husy signal,*SW-1.1 (p 'ition.5) Aarmature fvffof relay, armature of relay T andcoils f 36 to groii 'ndij\' The toll oni no " circuit extends fromleases the connector or leaves itin the set position 'until .the calledline becomes idle.

If the desired line is idle, relay T be.-

move into position 4, the circuit leing closed from grounded battery,through resistance 4, SIX (position 4), TII vto ground. The magnet SSMreceives. an impulse through 'U33 and moves the side switch wipersintoposition 5. While the side switch wipers are moving from position 4 to5, and in position of these wipers, the relay T is maintained energizedby current flowingrin the following circuit: grounded battery,resistance 4, 'SIX (position 5), o, 1522, TH, to ground. At the sametime a busy potential is connected to the test terminal ^42 of thecalled line through a resistance 3 and SY (position 5)'. c

If the desired subscriber is engagedt in Iconversation with a localsubscriber, then upon the completed setting of the connector under thecontrol of a toll operator and the movement of\ the, side switchwipers'- into position 4.relay'l B being tem oiarily deenergized, relayT becomes energized. The grounded battery through resistance 4, SIX(position 4), T, ground. The magnet 'SSM then ,receives an impulsethrough I2 and 033, and causes the movement of the side switch wipersinto position 5. 'The toll operator now hears the conversation on theline and understands thereby that the called subscriber is engaged in. alocal'conversation. Thel toll opeator then informs him of the incomingtoll c'all and the impending severance. of the local connection. Thetoll operator then again causes the temporary'deenergization of relayB.v A circuit -is now closed from grounded battery, through b2, a",l`SII (position 5), S"I (position 5), SSM, ground, and upon thesubsequent energization of relayI B, the magnet SSM causes the sideswitch wipers to move into position 6; In this position`of-theside'switch, a circuit is closed through I2, v3?, b and SVI for themagnet SSM, and the side lswitch wipers are moved into position 7 Theside switch wiper Sm now connects a ten-volt battery to the aconductor-of the local connection, and side switch wiper SWa ground tothe .b conductor of the local connection. In response f to-this, thelocal connection is severed in the well-known manner, as described' inBritish Patent' No. 2,672 of 1912. If the desired subscriber. was thecalling party of the local connection, then his line switch is released,and if he was the desired party in the local connection, the connectorof that connection is released. Battery is then su plied through testterminal 42, side switch V and conductor 4 8 to the II winding of `relayY. This. relay becomes energized and attracts its armature Y. ATheinterrupter I2 is then connected to the magnet SM, and the latter causesthe movement of the side switch wipers into position 8. lf thedesiredsubcomes energized when. the side swltch wipers scriber has replaced hisreceiver, relay Y will be deenergized. The toll operator may then causethe signaling of the desired substatlon. B and energizing relay X, theoperator may cause the establishment of a circuit for the ringing lrelayfrom grounded battery, through'- "b2", @27, SH, RI, y, to ground. lVhenthe called subscriber removes his re- By temporarily deenergizingrelay"- ceiver from the Switchhook, the relay Y is energized| by acircuit including the conductors@y and b 1n series.

actuated, whereupon she causes the severing of the connection, by theremoval ofk her cord circuit from the jack in which the conductors a, b,and c terminate. Relay B becomes deenergized and in the same manner 'as-above described, causes the energization lofthe magnet-s SSR andvCR forreleasing f the sideswitch and the connector.

)Vhat is claimed is: f

1. In 'a .telephone exchange system', -a connector switch having movable,an'dl'sta-tion'- ary contacts, tolllines arranged yfor conjnection tosaid movable contacts, local lines 1 terminatingin said stationarycontacts and arranged for connection to( said movable contacts, meansoperable through anyone of said lines for causing said connector to moveits movable contacts on to the stationary contacts of a desired line,`automatic testing mea-ns associated with said connector for testing thebusy or idle condition of the, desired line, 'automatic l guardingmeans-associated with said connector-for `Inaltinglthe line connectedwith; busy, auto-- matic switching means operable in response to thesetting of said connector over a local line for operating lsaid testingandg'u-arding 4 meansfmea-ns lcontrollable through a toll line in makingconnection with the desired line for preventing `the operation of said-`testing and` guarding .means so that saidl desired line kwill not busytoother switches, andv a"manually operable 'sw-itch operated at will forcontrolling the yoperation of said testing and guardingV means through atoll. line to lguard against seizure of said desired line by'otherfswitches f'f 2. In a telephone system, connector contacts, tolllines arranged for,v connecti 1 ,switchesfi having movable and stationyY to said movable contacts', loca-1' linestermif nating in saidstationaryv contacts. and ar^ ranged for connection to-said vmovable.con- ,T169

' for connecting with the stationary terminals thereto.

of a desired line whether said line is busy or not, mea-ns formaintaining Said last mentioned connection without making said line testbusy toother connector switches having access thereto, andmeansthereafter controlled at will bythe operator for com? p letingtelephonie connection with said desired line and for making said linebusy tol other connector switches having access thereto.

3. In a telephone system, a connector switch having movable andstationary con- Vtacts, toll lines arranged for connection to saidmovable contacts, means operable through any one of said lines forcausing said connector to move its movable contacts on to the stationarycontacts of a desired line, means for connecting with the stationaryterminals of a desired line whether said line is busy or not, and meanseffective if the line is idle for maintaining saidlast mentionedconnection and for preventing said connector from making said yline testbusy to otherconnector switches having access 4. In a telephone system,a connector switch having movable and stationary-contacts, toll linesarranged for connectie to said movable contacts, means operable throughany one of said lines for causing said connector to move its movablecontacts on to the stationary contacts of a vdesired line, means forconnecting with the stationary terminals of a desired line Whether saidline is busy or not, means for maintaining said last mentionedconnection without makingvsaid line test busy to other connectorswitches having access thereto, and means thereafter controlled at willby the operator for completing telephonie connection with said desiredline and making the saine busy to other connector switches havingaccessv thereto. l l

5. In a telephone system, a toll connector drectively controlled by anoperator for selecting a desired line, means in said conne-3- tor fortesting the selected line, means for preventing the operation of saidtesting'y means when the line is selected, and opera-l tor controlledmeans for causing the testing operationto take place at any desired timethereafter.

6. In a; telephone'system, a toll connector directively controlled by anoperator for selecting a desired line, means inl said con,

nector for -making the selected line busy ins ca set is idle whenSelected, and means for preventing the operation of said busying meansIwhile maintaining the connector in operated selective position.

' 7 In a. telephone system, a toll connector directively controlled byanoperator for selecting a desired line, means in said connector` lfortesting the selected line, means for preventing the operation of saidtesting means when the line is selected, operator controlled means forcausing the testing operation to take place at any desired timethereafter, and means effective in case the line is found busy forcompleting or barring the connection depending on whether theselectedline is busy in a loc-al connection or in a tollconnection'.

8. In atelephonev system,- a combination toll and local connector foruse by an operator or by local subscribers in selecting and connectingwith called lines, means in said connector for testing a called line assoon as selected in case the connector is in use by 'a local subscriber,and means for delaying and connecting with called lines, means in saidconnector effective automatically to make 'an idle called line busyas'soon as the same is selected in case the'connectoi' is in use by alocal subscriber, and means whereby' in case the said connector is inuse by the operator an idle called line is made busy at the will of-theoperator.

10. In a telephone system; a combination toll and local connector foruse by an operator or by local subscribers inv selecting and'connecti'ngwith called lines, anfl busy testing means in said connector operableautomatically or at the option of the calling party depending on whethersaid connector 1s being used by a local subscriber or by the operator.li i 11. In a telephone system, a. combination toll and local connectorfor use by an operator or by local subscribers in selecting andconnecting with called lines, a multi-position switching device in saidconnector. la test circuit closed in one position of said device if theconnector is in use'by a local subscriber and closed in a different.position if Said connector is in use by the operator.

12. In an automatic telephone system, an automatic switch controlled byan operator` for selecting a subscribers line, a key at the operatorsswitchboard,- and means in said switch requiring two successiveactuations of said key to signal the called subscriber.

13. Im an automatic telephone system, an automatic connector switchcontrolled byan operator for selecting. a subscribers line, 'said lineremaining in idle condition,means controlled by the operator at will formaking said line busy, and additional means means controlled by theoperator at will for thereafter controlled'by the operator at willmakin` said line busy and ringingk the called v for signalling thecalled subscriber. Subscrl r. 11

' 14. In -an automatic telephone system, an In Witness whereof, Ihereunto subscribe automatic connector switch controlled by my name.

an operator for selecting a subscribe'isline, ,said line remaining inidle condition, and GEORG FRUBING.

